i just built mine recently...Havent even driven it yet.....but i have an issue as well with lack of rebound in the front. Mine doesnt stay dow.It comes back up, but not as much or as smoothly as it should.
i havent tried to isolate the issue yet.....Just mentioning that i have a similar issue....n im pretty sure ive seen it mentioned by others as well.
Cant recall seeing a fix though.